If you want to create a form for someone to sign up as a contact or for someone to make a donation, do you create an event? Or, are there forms somewhere to use?
Welcome to SE! You certainly don't want to create an event for either of those scenarios. You just need to look at a bit more documentation (daunting at first but well worth looking through it all to see all the capabilities of CiviCRM).
For creating signing up as contact - the use profiles (see https://docs.civicrm.org/user/en/latest/organising-your-data/profiles/)
For the donation you should create an online contribution (see https://docs.civicrm.org/user/en/latest/contributions/online-contributions/)